This invention relates to welding electrodes and particularly to an elongated flexible welding electrode suitable for continuous electric welding purposes.
Heretofore, welding electrodes for electric welding have been provided in short rods having a length of approximately 30 centimeters. The welding electrode or rod consists of a rigid metal core with flux material coated on its outside surface. In use the rod is mounted to a welding handle or gun which conducts a large current through the welding rod to form a weld on the metal welding surface. Such welding rods provides a generally high quality and good surface appearance weld. It can be used or adapted for welding to a large variety of metal surfaces and a relatively simple welding equipment is required. However, such short length welding electrodes are not suitable for continuous welding purposes since the welding process must be frequently disrupted in order to install new rods when each rod has been expended. Furthermore, there is a considerable wastage of the welding electrodes. This is due to that at least 2 centimeters of one end of the rod must be uncoated to provide the conducting surface for supplying the welding current to the rod. Since such end portion of the electrode is not provided with the welding flux material it can not be used for welding. Also, due to the welding technique employed, normally an additional 3 centimeters of the rod can not be used. Thus, for a common 30 centimeters welding rod, there is at least 5 centimeters of it is wasted, which amounts to a total of at least 15% of wastage of the electrode. Moreover, since the welding current is applied through the whole length of the rod which, due to the inherent current resistance of the metal rod, reduces the effective amount of current delivered to the tip of the rod for the welding operation. For the above reasons the efficiency of using welding rods for welding is low.
Another disadvantage of using welding rods, is that, for a large area to be welded, a plurality of weld areas would be formed since separate welding rods must be used during the welding operation; thus there are a plurality of joints among the non-integrally formed weld areas. These joints inherently reduce the strength of the weld.
Attempts have been made to produce elongated welding electrodes by providing the metal in a tubular form with the welding flux material contained within the welding tube. However, such tubular welding electrodes are difficult and expensive to fabricate.
Furthermore, heretofore, it has been unable to provide an elongated welding electrode which has such flexibility that any desired length of it may be wound on a reel for convenient storage purposes as well as for use in a continuous welding operation. This is due to that the welding flux materials are relatively brittle, so that it is not conducive for flexing. Any attempt to wind a welding electrode with a welding flux material coating provided thereon would result in the flux coating from breaking apart and separating from the metal core of the electrode.